Scientists have discovered a key marker in the blood of middle-aged adults that can detect the building blocks of cancer, chronic heart disease and other serious health conditions.

The new inflammatory marker is more accurate than the one that is currently used, the study said.

The new compound, known as IL-6 is more accurate in assessing the risk of mortality, in both the short and long-term, than the previously used α1-acid glycoprotein (AGP).

Lead author Professor Archana Singh-Manoux, from University College London, said: “Omics technologies are exciting, as they allow the concurrent assessment of many biomarkers, some of which may turn out to be important to detect preclinical states of diseases or be markers of future disease.”

The study, published in the Canadian Medical Association Journal, included data collected between 1997 and 1999 on 6,545 men and women aged 45 to 69 years.

“The latter was found in a recent metabolomics study to be a strong predictor of death within five years.

“When a recent metabolomics study highlighted the importance of AGP, our question was how relevant is this marker when compared to other known inflammatory markers.

“The novelty of our approach lies in being able to assess risk of mortality in the short- and long-term.

“Our findings show IL-6, which is already known to be important to heart disease, to do better than AGP.

“Research on biomarkers is progressing fast, and it is important to undertake checks like in the one in our study, to shape future research on biomarkers.”

In a related commentary, Dr Paul Ridker, from the Centre for Cardiovascular Disease Prevention at Harvard Medical School, said: “Biomarker discovery is crucial for thinking about new treatment targets.